1. Technical Field of the Invention
The present invention relates to a hinge structure of rotary door. An upper section of the rotary shaft of the buffering rotary hinge is formed with two opposite ring seats. A flange body is slidably fitted around the rotary shaft between the ring seats. The lower section of the rotary shaft is disposed with a piston body slidably fitted in an oil cylinder to form a buffering rotary hinge, whereby the closing of the door is buffered and the door can be easily opened. The buffering force at the end stage of closing of the door is released to accurately close the door.
2. Prior Art
FIGS. 1 and 2 show a conventional mechanical hinge structure of rotary door. The hinge 10 has a rotary shaft 11 around which an insertion seat 12, a rotary spring 13, a ring-shaped flange body 14, a ring-shaped slide seat 15, a compression spring 16 and a mating pad seat 17 are sequentially fitted. The inner rim of the insertion seat 12 is formed with annular ratchets 18 and the top edge thereof is disposed with a pushing projection 19. The rotary shaft 11 is formed with a transverse hole 20 in which a resilient member 21 and a one-way ratchet 23 with a guide slot 22 are fitted to abut against the annular ratchets 18. A restricting member 24 is slidably inserted from the top of the rotary shaft 11 into the guide slot 22. Two ends 25 of the rotary spring 13 between the insertion seat 12 and the flange body 14 are respectively inserted into an upper and a lower insertion holes 26. Between the flange body 14 and the slide seat 15 are disposed corresponding projecting wedge edge 27 and recessed wedge edge 28. The flange body 14 is formed with an insertion hole 29 and the slide seat 15 is formed with a slide channel 30, whereby when inserted into the casing 31 of the hinge and relatively rotated, the slide seat 15 pushes the lower compression spring 16. When rotarily restored, the compression spring 16 and rotary spring 13 relatively act on the projecting wedge edge 27 of the flange body 14 and the recessed wedge edge 28 of the slide seat 15 to slide and rotate so as to automatically restore and close the door.
However, in use, without any buffering device, the mechanical rotary hinge 10 will act on the door to close the door at a high speed with great noise. In addition, due to collision, the door is apt to be damaged. Moreover, the door is disposed with at least two mechanical rotary hinges 10 which exert an excessively great reactional pushing force when the door is opened. Therefore, it is difficult to open the door.